74HC147N PHILIPS

Document overview

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Technical content

Product specification File under Integrated Circuits, IC06 December 1990 INTEGRATED CIRCUITS 74HC/HCT147 10-to-4 line priority encoder For a complete data sheet, please also download:

  • The IC06 74HC/HCT/HCU/HCMOS Logic Family Specifications
  • The IC06 74HC/HCT/HCU/HCMOS Logic Package Information
  • The IC06 74HC/HCT/HCU/HCMOS Logic Package Outlines

Philips Semiconductors Product specification 10-to-4 line priority encoder 74HC/HCT147

FEATURES

  • Encodes 10-line decimal to 4-line BCD
  • Useful for 10-position switch encoding
  • Used in code converters and generators
  • Output capability: standard
  • ICC category: MSI GENERAL DESCRIPTION The 74HC/HCT147 are high-speed Si-gate CMOS devices and are pin compatible with low power Schottky TTL (LSTTL). They are specified in compliance with JEDEC standard no. 7A. The 74HC/HCT147 9-input priority encoders accept data from nine active LOW inputs ( A0 toA8) and provide a binary representation on the four active LOW outputs Y0 toY3). A priority is assigned to each input so that when two or more inputs are simultaneously active, the input with the highest priority is represented on the output, with input line A8 having the highest priority. The devices provide the 10-line to 4-line priority encoding function by use of the implied decimal “zero”. The “zero” is encoded when all nine data inputs are HIGH, forcing all four outputs HIGH. QUICK REFERENCE DATA GND = 0 V; T amb = 25°C; tr = tf= 6 ns Notes 1. C PD is used to determine the dynamic power dissipation (PD inµW): PD = CPD × VCC 2 × fi+∑ (CL × VCC 2 × fo) where: fi= input frequency in MHz fo = output frequency in MHz ∑ (CL × VCC 2 × fo) = sum of outputs C L = output load capacitance in pF VCC = supply voltage in V 2. For HC the condition is VI= GND to VCC For HCT the condition is VI= GND to VCC − 1.5 V

ORDERING INFORMATION

See “74HC/HCT/HCU/HCMOS Logic Package Information”. SYMBOL PARAMETER CONDITIONS TYPICAL UNIT HC HCT tPHL / tPLH propagation delayAn toYn C L = 15 pF; VCC = 5 V 15 17 ns C I input capacitance 3.5 3.5 pF C PD power dissipation capacitance per package notes 1 and 2 30 33 pF

Philips Semiconductors Product specification 10-to-4 line priority encoder 74HC/HCT147 PIN DESCRIPTION PIN NO. SYMBOL NAME AND FUNCTION

8 GND ground (0 V)

9, 7, 6, 14 Y0 toY3 BCD address outputs (active LOW) 11, 12, 13, 1, 2, 3, 4, 5, 10A0 toA8 decimal data inputs (active LOW) 15 n.c. not connected 16 V CC positive supply voltage Fig.1 Pin configuration. Fig.2 Logic symbol. Fig.3 IEC logic symbol.

Philips Semiconductors Product specification 10-to-4 line priority encoder 74HC/HCT147 FUNCTION TABLE Notes 1. H = HIGH voltage level L = LOW voltage level X = don’t care INPUTS OUTPUTS A 0 A 1 A 2 A 3 A 4 A 5 A 6 A 7 A 8 Y3 Y2 Y1 Y0 HHHHHHHHHHHHH X X X X X X X X X X X X X X X X X X X X X X X L X X L H X L H H L H H H L L H H H H L L H H L L L H L H X X X X X X X L X X L H X L H H L H H H H H H H H H H H H H H H H H H H H H H H L L H H H H L L L H L H L HHHHHHHHHHHL Fig.4 Functional diagram.

Philips Semiconductors Product specification 10-to-4 line priority encoder 74HC/HCT147 Fig.5 Logic diagram.

Philips Semiconductors Product specification 10-to-4 line priority encoder 74HC/HCT147 DC CHARACTERISTICS FOR 74HC For the DC characteristics see“74HC/HCT/HCU/HCMOS Logic Family Specifications”. Output capability: standard ICC category: MSI AC CHARACTERISTICS FOR 74HC GND = 0 V; tr = tf= 6 ns; CL = 50 pF SYMBOL PARAMETER Tamb (°C) UNIT TEST CONDITIONS 74HC VCC (V) WAVEFORMS +25 −40 to+85 −40 to+125 tPHL / tPLH propagation delay An toYn 160 200 240 ns 2.0 4.5 6.0 Fig.6 t THL / tTLH output transition time 110 ns 2.0 4.5 6.0 Fig.6

Philips Semiconductors Product specification 10-to-4 line priority encoder 74HC/HCT147 DC CHARACTERISTICS FOR 74HCT For the DC characteristics see“74HC/HCT/HCU/HCMOS Logic Family Specifications”. Output capability: standard ICC category: MSI Note to HCT types The value of additional quiescent supply current (ΔICC ) for a unit load of 1 is given in the family specifications. To determineΔICC per input, multiply this value by the unit load coefficient shown in the table below. AC CHARACTERISTICS FOR 74HCT GND = 0 V; tr = tf= 6 ns; CL = 50 pF AC WAVEFORMS PACKAGE OUTLINES See “74HC/HCT/HCU/HCMOS Logic Package Outlines”. INPUT UNIT LOAD COEFFICIENT A3,A4,A7,A8 1.50 A5,A6,A0,A1,A2 1.10 SYMBOL PARAMETER Tamb (°C) UNIT TEST CONDITIONS 74HCT VCC (V) WAVEFORMS +25 −40 to+85 −40 to+125 tPHL / tPLH propagation delay An toYn 20 35 44 53 ns 4.5 Fig.6 tTHL / tTLH output transition time 7 15 19 22 ns 4.5 Fig.6 Fig.6 Waveforms showing the decimal data inputs (An) to output (Yn) propagation delays and the output transition times. (1) HC : VM = 50%; VI= GND to VCC . HCT: VM = 1.3 V; VI= GND to 3 V.